Tony Stewart let his secret out this week on Twitter: He was back testing in a sprint car, feeling like he'd never left. ''Nope.'' Stewart kept mum Friday about any future plans in sprint cars, more than nine months after he broke his leg in a crash that cost him the rest of the 2013 season. I don't want it to be a cluster.'' The three-time NASCAR champion missed the final 15 races last year after breaking his leg in two places during a sprint car crash in Iowa. His sprint car had been fitted with safety improvements to the torque tube to prevent an injury like the one he suffered. More...